Luther’s Works: The American Edition, published by Concordia and Fortress Press between 1955 and 1986, comprises fifty-five volumes. These are a selection representing only about a third of Luther’s works in the Latin and German of the standard Weimar Edition, not including the German Bible.
These two lectures were given about a decade apart. The first in point of time, the Hebrews lectures, were delivered in the "Theses" year, 1517. Luther was finishing his lectures on Hebrews when he was summoned to Heidelberg to attend a convention of the German Augustinians order in April 1518. Presumably the Augustinians were to settle the controversy precipitated by Luther in the Ninety-five Theses, but instead of receiving a rebuke, Luther gained a new following at Heidelberg, especially among the younger theologians. The lectures on Titus and Philemon were given ten years later, when controversy and polemics had become a necessary part of Luther's daily routine. Then too, Luther's commentary shows him to be most deeply concerned about imitating his favorite apostle in preaching effectively and relevantly.